AKI Flashcards
1
Q
Drug dosing in AKI
A
- Decision to dose adjust medications should be a clinical decision based on CrCl, UO, and suggested dosing guidelines
- Calculate CrCl and review UO daily
- Dose reduce based on suggested guidelines
- Consider serum drug concentrations
- Dose adjust back up when renal function recovers
2
Q
AKI pt evaluation steps
A
- Discontinue nephrotoxic medications
- Identify cause of AKI
- Treat AKI
- Renally dose adjust medications
3
Q
Post renal AKI diagnosis
A
- Renal imaging
- UA: Hematuria, crystals
- BUN:SCr <15:1
- FeNa > 1%
- No daily change in SCr
- Anuria
4
Q
Be able to identify and treat different types of AKI
Know how to calculate a CrCl and UO
Be familiar with prevention strategies
Know common medication nephrotoxins
Dose adjust medications in AKI
A
5
Q
Urinary Analysis
A
- Hydration
- Color
- Dark yello=dehydrated
- Specific gravity
- >1.020 = dehydration
- Color
- Infection
- WBC
- >50= infection
- Leucocyte esterase
- Production of neutrophils
- 1+,2+, 3+ = infection
- Nitrites
- made by bacteria
- Positive= infection
- WBC
- Kidney Function
- Protein, 1+,2+,3+ = intrinsic renal failure
- RBC, Positive = Traumatic catheterization, tumor, nephrolithiasis
- Casts
- Different types (hyaline, granular)
- Positive = intrinsic renal failure
- Crystals
- Different types (uric acid, calcium oxalate)
- Positive = tumor lysis syndrome or nephrolithiasis
6
Q
Types of Acute Kidney Injury
A
Prerenal
Intrinsic
Postrenal
7
Q
Prerenal AKI
A
- Occurs prior to the kidney
- Reduction in blood volume
- Reduction in bloodflow to the kidney
- Hypotension
- Sepsis
- Heart or liver failure
- Bleeding
- Renal thrombosis
8
Q
AKI definition
Decline in?
Increase?
Increase?
A
- Abrupt reduction in kidney function
- Decline in urine output
- Increase SCr
- Increase BUN
9
Q
Post renal failure tx
A
- Remove obstruction
- Nephrolithiasis- lithotripsy
- Tumore= Surgery
- Stricture = urinary stent
- BPH = doxazosin, tamulosin, finasteride
- Hydronephrosis
- Nephrostomy tube
10
Q
Prerenal Failure Tx
A
- Restore blood volume
- IV fluids- aggresive rehydration with normal saline or balance solution
- Discontinue diuretics
- Restore blood flow
- Blood - indicated in bleeding situations
- Treat the underlying cause conditions (heart failure, sepsis)
- Discontinue and limit nephrotoxins
11
Q
Types of intrinsic AKI
A
ATN and AIN
12
Q
CRRT
A
- Indicated when blood pressure too low to tolerate HD
- Continual removal of fluids and solutes so more resembles actual kidney function
- Differ in way the solute is removed
13
Q
Diagnosing prerenal AKI
A
- Pt hx, N/V, diarrhea
- Dry mucous membranes, decrease jugular venous distension
- UA: Dark yello, high specific gravity
- BUN:SCr > 20:1
- Urinary Na < 10
- FeNa < 1%
- Oliguria
- Rapid change in SCr with tx
14
Q
AKI symptoms
A
- Fluid overload
- SOB
- Peripheral edema
- wt gain
- Urinary Changes
- Decreased or painful urination
- Change in color or odor
- Uremia
- N/V
- Itching
- Fatigue
- Confusion
- Situation
- Flank pain
- HA
- Arthralgia
15
Q
AKI complications
A
- Fluid overload
- Pulmonary and peripheral edema
- IV bolus loopd diuretics –> Continuous infusion loop diuretics —> hemodialysis
- Electrolyte abnormalities
- Increase K, Phosphorus, magnesium
- Hyperkalemia most common and concerning
- Blood glucose irregularities
- Hyperglycemia common due to impaired glucose homeostasis and metabolic stress
- Insulin eliminated by the kidneys so may result in hypoglycemia
16
Q
Drug dosing in AKI
HD
and
CRRT
A
- Assume little to no UO
- Drug elimination dependent on filter type, flow rate, amount of time on HD and drug characteristics
- Molecule size, protein binding, ionized form
- Dosing different for each medication
- Bolus dosing daily or 3 times/week after HD
CRRT
- Dependent on flow rate but usually assume normal renal function with no drug adjustment
17
Q
ATN -
A
Nephrotoxic meds
- ACEs
- ARBs
- NSAIDs
- Amnoglycosides
- Vancomycin
- Amphotericin B
18
Q
ATN- Rhabdomyolysis
A
Rhabdomyolysis
- breakdown of muscle cells releases damaging proteins into systemic circulation
- Seen by an increase in CPK and myoglobin
- Myoglobin specifically damages kidneys
- Serum myoglobin level useful in diagnosis
- Treat with fluids such as normal saline or sodium bicarbonate
19
Q
Risk factors for AKI
A
- Male
- AA
- Advanced Age
- CKD
- DM
- Heart or Liver Disease
- Surgery
- Sepsis
- Hypotension
- Volume depletion
- Diarrhea
- Vomiting
- Dehydration
- Medications
20
Q
AKI monitoring
A
- Daily wts
- Fluid intake and UO
- Daily serum creatinine
- daily serum electrolytes
- Vital signs
- Symptoms (edema)
21
Q
Post Renal AKI
A
- Occurs after kidney
- Caused by an obstruction between kidney and urethra
- Nephrolithiasis
- Uric acid crystals
- Tumor
- Stricture
- BPH
22
Q
Type of renal replacemen
A
Hemodialysis
Rapid removal of fluids and solute
Performed daily in acute setting or 3 x
common complication hypotension
23
Q
AKI treatment goals
A
- Restore renal function to baseline
- Identify the cause
- Reverse the cause
- Limit damage
- treat symptoms
- Manage complications
24
Q
Modification of Diet in Renal Disease (MDRD)
A
- Calculate an eGFR
- Better estimates renal function
- Utilized to stage renal failure
25
Indications for renal replacement therapy
AEIOU
* Acidosis
* Electrolytes
* Intoxication
* Overload
* Uremia
26
ATN
Contrast Induced Nephropathy
* Dye causes free radical formation which is directly toxic to the kidneys
* SCr increase 2-5 days after contrast exposure
* Prevention is key
* Normal saline or sodium bicarb infusion
* N-Acetylcysteine
27
SCr
* Must know pts baseline
* Trend in SCr more important than acutal level
* Lag in SCr change by 1-2 days from original insult
* Use of GFR equations limited as these assume stable renal function
28
Urine Output
* Most acute marker of change in renal function
* Conern when \<0.5 mL/kg/hr
* Complicated by volume status, diuretic use and obstruction
* Nomentclature
* Nonoliguric is \> 500 ml/day
* Oliguric \<500 ml/day
* Anuric \<50 mL/day
29
Acute Interstitial Nephritis AIN
* Delayed hypersensitivty rxn
* Tubular and Interstitial inflammation
* Symptom triad, Fever, Rash, Urine Eosinophils
* Medications most common cause
* beta lactam antibiotics
* NSAIDs
* Trimethoprim/ sulfamethoxazole
30
Review
* Normal kidney function markers
* Definite, detect and classify AKI
* Types of AKI
* Diagnosis and tx
* Prerenal, intrinsic and postrenal
* Renal replacement therapy
* Complications of AKI
* Drug dosing in AKI
* AKI prevention
31
Fractional Excretion of Sodium
* Reflection of ability of kidney to concentrate urine
* Not accurate if recent diuretic use
32
AKI Markers and lab testing
* SCr
* UO
* Urinary Analysis
* Urine Electrolytes
* Renal imaging
33
Urine output criteria
Risk
injury
Failure
Loss ESRD
* UO \< 0.5 ml/kg
* UO \< 0.5 ml/kg x 12 hours
* UO \< 0.3 ml/kg x 24 hours or anuria x 12 (oliguria)
* Persistent ARF = complete loss of renal function \> 4 weeks
* ESRD
34
Kidney Function Markers
Urine Output
Normal Output?
How to calculate?
* Best marker of urine function
* Normal urine output = 0.7-1 ml/kg/hr
* To calculate determine amount of urine output and divide by the pts weight and time period
35
Kidney Function Markers
Serum Creatinine
SCr \< 1
Affected by age, gender, muscle mass, diet and hydration status
Some medications may increase
36
Intrinsic AKI
* Direct damage can be due to the glomerulus or tubules
* Kidney injury a result of
* Ischemia
* Toxins
* Medications
* Contrast dye
* Proteins (myoglobin)
37
AKI classifications
Staging Criteria
Types of Staging systems
* Staging
* SCr change for baseline
* GFR change from baseline
* Urine output over specified time period
* Systems
* Risk, Injury Failure, Loss of Function and ESKD (RIFLE)
* Acute Kidney Injury Network (AKIN)
* Kidney Disease: Improving global Outcumes (KDIGO)
38
glomerular filtration rate
equation
(140-age) x wt (kg)
/
72 x SCr
if female x by 0.85
39
GFR Criteria
Risk
Injury
Failure
Loss
ESRD
* Increased creatinine x 1.5 or GFR decrease \> 25%
* Increased creatinine x 2 or decrease \>50%
* Increased creatinine x 3 or \>75% decrease or creatinine \> 4 mg per 100 mL
* Persistent ARF = Complete loss of renal function \> 4 wks
* ESRD
40
Renal imaging
Renal ultrasounds
Abdominal CT scan
41
Intrinsic renal failure treatment
* Discontinue offending agent
* IV-fluids- normal saline or balanced solutions
* Limit nephrotoxins
42
Normal Renal Function
A WET BED
* A- Acid/base balance
* W-Water balance
* Electrolyte balance
* Toxin Removal
* Blood pressure control (Renin)
* Erythropoietin production
* Vitamin D activation
43
Intrinsic AKI diagnosis
* UA: Protein, granular casts, eosinophils
* BUN:SCr \< 15:1
* FeNa \> 1%
* Slow change in SCr with tx
